Packaging systems are an important aspect of manufacturing. A significant expense in manufacturing is the erecting a box from a blank, packing the box with product, and sealing the box after filling. Containers include, for example, boxes, cartons and similar packages made of paper, cardboard and similar materials. Until recent times, human hands have performed the tasks of assembling and packing containers.
While box-sealing mechanisms are well known in the art, the ability to change a packaging line to seal a different type or sized carton often requires the shutting down of the packaging line to adapt the sealing machinery to the new carton. This adaptation not only causes a pause in production, but may require both the time and expense of mechanics changing over the machinery and attaching different packaging machinery parts. In such a case, space is needed to store the different packaging machine parts and a system to keep track of the parts needed for various sized boxes, and adding to the overall cost of the packaging system.
Increasingly, automated systems are being developed to reduce the human and material resources needed to assemble, pack and seal different containers as well as reduce the time needed for adaptation to different packaging operations. It is well known that containers are available in a wide range of configurations, each configuration having specific closing and sealing requirements. For example, the Regular Slotted Container (RSC) has four flaps on the bottom and an identical number of flaps on the top, namely a pair of opposed minor flaps alternating with a pair of opposed major flaps. Numerous methods have been proposed which are used to seal RSC boxes.
Typically, the erecting and sealing of a regular slotted container proceeds along the following lines. A blank is assembled into a box-like configuration and glue is applied to specified surfaces of the bottom flaps. The bottom flaps are then folded and held in that position until the glue is set. This process can be carried out either manually or by machine and is not overly difficult since the case is empty at this stage and pressure can be applied from above and below so as to sandwich the bottom flaps in the closed position until it is assured that the glue is set. Machines specially adapted for erecting a folded blank into a box configuration, applying glue to the bottom flaps and folding the same, are known in the art.
As discussed above, the filling or packing of cases can be performed manually or, increasingly by mechanical means. Robotic packing machines are increasingly being used to fill cases with product.
The process of closing the case top is, however, not as easily accomplished. Equipment access from inside the erected case, to hold the top flaps sandwiched together in a closed position, is precluded. If the contents fill the erected case to the top, and if such contents are solid, external pressure from above alone may be effective to press the top flaps against such contents until the glue is sufficiently dried. Such an unpredictable arrangement is unacceptable for high-speed commercial sealing operations. Without predictable supporting during the gluing operations, the top flaps cannot be sealed effectively in that fashion. Machines specially adapted for closing case tops for RSC cases are exemplified by machinery described in for example, U.S. Pat. No. 4,524,560.
Of course, different cases require different sealing strategies. Full flap or side sealed boxes, i.e., those cases having two top flaps with end portions which are glued to the sides of the box cannot be effectively closed using exactly the same case sealing mechanism as a RSC box. What is required is a mechanism that urges the two top flaps into a horizontal position and then urges the four end portions of the two top flaps into a vertical position against the pre-glued sides of the box.
There is a demand therefore for a mechanism that efficiently closes side seal boxes and is easily and quickly adaptable to different sized containers. The present invention satisfies the demand.